Method of making aniline and similar amine compounds



Patented Aug. 27, 1929.

UNITED S A PATENT OFFICE.

WILLIAM 'H. WILLIAMS AND JOSEPH w. nni'rzron, or MIDLAND, :urcmemv nssmnons '10 rrnn now cnmrrcar. COMPANY; or mrnnmn, MICHIGAN, a (201120- RATION or MICHIGAN.

METHOD OF MAKING- ANILINE AIINE COMPOUNDS.

R Drawing. Application filed April 22,

.Various attempts have been made to prepare arylamines from the corresponding halogenated aromatic hydrocarbon derivatives by direct reaction between the latter and ammonia. at an elevated temperature and corresponding high'pressure but so far as we are aware, no commercial success has attended efforts heretofore made alon this line. In the main such failure may e attributed to inability to secure a proper'yield of the desired end product, so that the process is unprofitable. In certain cases where a relatively high yield has been obtained it :hasbeen found upon trial that the reacting mixture has such a destructive efiect on ,the containers or apparatus in whicli the process is conducted as to render such processes impracticable.

Inv our application filed March 1, 1926,. Serial No. 91,565, we disclose a method more particularly directed to the pre aration of aniline or phen lamine C H .N 2 from the corres onding alogenated benzene, e. g. chloro enzene, by a process of the general type described above wherein the reaction is greatly promoted and a much higher yield ofaniline obtained by the addition to the reaction mixture of certain ingredients. This method or process, it may be stated, has

proven entirely practicable when operated-- on a commercial scale, not only in the respects noted, but also in the important particular that the expensive apparatus required for carrying out such a high pres sure high temperature reaction has been 4 found unaffected by the reactionv mixture after a con'siderableperiod of use We have now further-extended our investigation of this improved process and find in the first place that it is applicable generally to the 1927. Serial No. 185,908.

The present improved process accordin ly consists of the steps hereinafter fully escribed and particularly ointed-out in the claims; the following escription setting forth but several of the various ways in whizh the principle of the invention may be use The following is given as a specific example of the procedure involved in carrying out our improved method or making of aniline, viz

In starting the operation a suitable quantity of chlorobenzene is mixed with a 25 to 30 per cent aqueous ammonia solution in .such amount as to furnish from 4 to 5 mol. of anhydrous ammonia to one mol. of chlorobenze'ne. This mixture is then charged with from 0.1 to 0.2 mol. of cuprous oxide, hydroxide, or chloride, or a mixture thereof, (the cuprous oxide or hydroxide being preferred) into a suitable closed reaction chamber, such as an iron autoclave capable of withstanding a working pressure as high as several thousand pounds, and the mixture thereu on heated with stirring to a tempera-' ture 0 from 150 to 250 degrees C. and with a correspondin pressure, viz, from 500 to 1500 pounds. he time of heating will vary with the temperature and pressure thus ap- 5 5 process for the plied, from 12 hours for the lower temperaat the higher tem- I A certain amount of phenol will be simultaneously formed'by hydrolysis of the chlor'obenzene, but this is limited or controlled by the excess of-ammonia employed. 'A small amount of diphenylamine,

is also formed as a side product; while the excess ammon a will remain of course, as

well as any unreacted chlorobenzene. In admixture, and to this end the autoclave should 1 Y dition to reacting with the latter, the amsaid to yield certain copper-ammoniacal.

compounds that are of special significance and interest, in the present connection.

from coming in contact with the reaction It is quite important that air be prevented I be initially'filled with ammonia gas and an for the cuprous chloride, oxide, or hydroxide atmosphere of ammonia therea ter mainpreviously specified. In' case, however,

tained, as the operation describedis repeated.

Upon completion of the reaction in the first or main stage of the operation, the products still in the form of a liquid mixture resulting therefrom are discharged under pressure of the ammonia gas in the autoclave into a suitable closed vessel for removal first of the free ammonia and then for the treatment of the other ingredients in such mixture as will now be described: These ingredients willinclnde the aniline oil containing unreacted chlorobenzene with some phenol as well as some diphenylami-ne; also the water from the aqueous solution of ammonia which willco ntain ammonium chlokali metal.

line and phenol ride with any excess of ammonia present;

There will also be dissolved in such aqueous,

solution and to a certain extent in the aniline oil the above-mentioned copper-ammoniacal com ounds. j v

T e treatment of'the foregoing mixture of ingredients and products resulting from the reaction consists in'the first place in the addition to the unseparated mixture of a,

caustic compound, using this term to include the oxide, hydroxide or equivalent compound of an alkaline-earth metal as well as an al- 'or (12) in an amount sufficient, in addition to thelforegoing to react with the phenol as we] a After treatment with the caustic composition the mixture is next subjected to steam distillation withthe result that ('a). where only the ammonia has been freed, the follow-' ing products Willbe distilled off iiizthe order stated, viz, such ammonia, chlorobenzol, aniamine, or (b) whereenough caustic compound has been' added to react with the phenol the follo ing products will. be distilled off in the order stated, viz, ammonia,

w chlorobenzol, aniline and diphenylamine, the

in the form of a sh ge,

phenate formed-by reaction of the caustic compound ,withthe' phenol remaining in solution. a s In either case there will also remain in thesolution a preci itate which settles out sultin from the reaction can with the aforesaid ile the base of this precipitate or sludge is undoubtedlycopper oxide, or hydroxide, its exact composition has not been ascertained, but after settling it is filtered and, if

offthefcaustic'comdesired, may be washed with water, steamed or blown with air,

but not too thoroughly dried in air, and is then used over again in a repetition of the process, being substituted Such caustic compound may be.

(together) and diphenyl such precipitate re-- there is a loss in copper, as may be deter,

mined by analysis, the deficiency may, if desired, be made up by adding more cuprous oxide or chloride to form the equivalent of that used in starting the process.

.The hereinbefore described process in its general aspects forms the subject-matter of our co-pending ap lication filed April 21, 1927, Serial No. 1 5,648, inwhich applica: tion specific claims are also made to cover the addition of the caustic com ound in an amount approximately just su cieiit to lib- In conclusion; it should'be stated that our improved process isapplicable not merely to aniline or 1 phenylamine, C,,H,,.NH,, but to the production or the homologues of aniline or the variou's arylamines'in general, as illus-,

trated byfthe following exam les, viz

monium -cuprous chloride and copper, readily yields 2. Chlorotoluene, CH C,,H

'3. Chloronaphthalene, G, H,'Cl, similarly yields C, H,NH naphthylamine.

4. Chloroanthra uinone, C',,H,-Q,Cl, simi larly yields C,',H,% none. I

Certain of the foregoing homologues. of

aniline or equivalent arylamines, it should further be explained, may not beseparable by dry distillation, but in such case separation may be effected by an extraction process using chlorobenzene or e uivalent solvent.

1 Other modes of applying the rinciple of our invention may be employe instead of the one explained, change being made as rel gards the method herein disclosed, provided the step or' steps stated by any of the following claims or the equivalent of "such st ted steps or steps be employed.

e therefore particularly point out and distinctly claim as our invention: 1. In a method of making an arylamine, the steps which consist-in reacting between I the corresponding halogenated aromatic hy-v copper compounds.

drocarbon and aqueous ammonia Solution in the presence of a cuprous compound, whereby a mixture of arylamine and an aqueous" solution containing various copper compounds is produced, such mixture also including ammonium halide and a phenol, adding a caustic compound in amount suficientto reactwit-h bothsuch halide and 'phenol and then distilling ofi' the arylamine, ,the

N H 'amino-anthraqui 1. Dichlorobenzene, q Hfi with am y C H,(NH,). phenylenediamine.

Cl, similarly yields CH,C H,NH toluidine.

. act with both phenol being left behind in the form of phenate solution.

2. In a method of making an arylamine, the steps which consist in reacting between the corresponding halogenated aromatic hydrocarbon and aqueous ammonia solution in the presence of a cuprous compound, whereby a mixture of arylamine and an aqueous solu tion" containing various copper compounds .is produced, such mixture also including ammonium halide and a phenol, adding a caustic compound in amount suflicient to resuch halide and phenol and then distilling off the arylamine, the henol being left behind in the form of p enate solution together with a precipitate formed from such copper compounds and repeating the first step, using such recipitate for the cuprous compound therein.

3. In a method of making aniline, thesteps which consist in reacting between a mono halogenated benzene an aqueous amonia solution in the presence of a cuprous compound,

whereby a mixture of aniline and aqueous solution containing various'copper compounds is produced including ammonium halide and phenol, adding a caustic com ound in amount suflicient to react with th such halide'and phenol and then distilling oil the aniline, the phenol being left behind in the form of phenate solution.

4. In a method of making aniline, the steps which consist in reacting between a mono halogenated benzene and aqueous. ammonia solution in the presence of a cuprous compound, whereby a mixture of aniline and aqueous solution containin various copper com ounds is produced, suc mixture also inclu ing ammonium halide' and phenol, ad-

such mixture also precipitate ding a caustic compound in amount suflicient to react with both such halide and phenol and then distilling off the aniline, the phenol being left behind in the form of henate solution together with a precipitate ormed from such copper compounds, and repeating the first step using such precipitate for the cu rous compound therein.

5. In a method of making aniline, the steps which consist in racting between chlorobenzene and aqueous ammonia solution in the presence 0 mixture of aniline and aqueous solution containing copper c'om minds is produced such mixture also inclu ing ammonium chloride and phenol, adding a caustic compound in amount sufiicient to react with both such chloride and phenol and then distilling off the aniline, the phenol being left behind in the form of phenate solution.

6. In a method of making aniline, the steps which consist in reacting between chlorobenzene and aqueous ammonia solution inthe presence of on of aniline an aqueous solution containing various copper com unds is produced, such mixture also inclu ing ammonium chloride and phenol adding a caustic compound in amount suiiicient to react with both such chloride and phenol and then distilling ofi' the aniline, the phenol being left behind in the form of phenate solution together with a ormed from such copper compounds, and repeating the first step using such precipitate for the cuprous oxide there- Signed by us this 1st day of April, 1927.

WILLIAM H. WILLIAMS. JOSEPH w. BRITTON.

rous oxide, whereby a mixture cuprous oxide, whereby a 

